3GPP (3rd Generation Partnership Project) has standardized the W-CDMA as a third-generation cellular mobile communication mode and the service is sequentially started. HSDPA with higher communication speed has also been standardized and the service is started.
On the other hand, 3GPP is working on the standardization of the evolution of the third generation radio access (Evolved Universal Terrestrial Radio Access; hereinafter “EUTRA”).
The OFDM (Orthogonal Frequency Division Multiplexing) is resistant to multipath interference and suitable for high-speed transmission and is employed as the downlink communication system of EUTRA. The DFT (Discrete Fourier Transform)-spread OFDM of the single carrier frequency division multiple mode SC-FDMA (Single Carrier-Frequency Division Multiple Access) is capable of reducing a peak to average power ratio PAPR of a transmitting signal and is employed as the uplink communication system in consideration of cost and power consumption of mobile station apparatuses.
The OFDM (Orthogonal Frequency Division Multiplexing) is proposed for the downlink of the EUTRA. The single carrier communication system of the DFT (Discrete Fourier Transform)-spread OFDM is proposed for the uplink of the EUTRA.
As depicted in FIG. 12, the downlink of EUTRA is made up of a downlink pilot channel DPiCH (Downlink Pilot Channel), a downlink synchronization channel DSCH (Downlink Synchronization Channel), a downlink shared channel PDSCH (Physical Downlink Shared Channel), a downlink control channel PDCCH (Physical Downlink Control Channel), and a common control channel CCPCH (Common Control Physical Channel).
The uplink of EUTRA is made up of an uplink pilot channel UPiCH (Uplink Pilot Channel), a random access channel RACH (Random Access Channel), an uplink shared channel PUSCH (Physical Uplink Shared Channel), and an uplink control channel PUCCH (Physical Uplink Control Channel) (Non-Patent Literatures 1 and 2).
A configuration of the downlink is depicted in FIGS. 13 and 14. One resource block is made up of twelve sub-carriers and seven OFDM symbols. One sub-frame is made up by using two resource blocks to assign the downlink shared channel PDSCH to at least one mobile station apparatus.
The downlink control channel PDCCH uses first to third symbols of the first resource block and the downlink shared channel PDSCH uses the rest of the OFDM symbols. The downlink pilot channel DPiCH is arranged in a scattered format in resource blocks as depicted in FIG. 13. FIG. 13 depicts an example when a base station apparatus has two transmission antennas and two types of pilot symbols exist. The downlink is made up of a plurality of resource blocks.
The downlink control channel PDCCH and the downlink shared channel PDSCH are received in a continuous reception mode and an intermittent reception (DRX: Discontinuous Reception) mode. As depicted in FIG. 15, the intermittent reception mode is introduced for suppressing the power consumption of a mobile station apparatus connected to a base station apparatus.
With regard to the intermittent reception mode, after the parameters related to the intermittent reception (such as a reception-ON period, a DRX interval, and a DRX start position) are specified for a mobile station apparatus by a base station apparatus, when the downlink control channel PDCCH and the downlink shared channel PDSCH are no longer received in the continuous reception mode, a shift to the intermittent reception mode is made at the DRX start position.
When the intermittent reception mode starts, the downlink control channel PDCCH is monitored during the reception period specified by the base station apparatus and, if downlink control data destined to its own mobile station apparatus is detected in the downlink control channel PDCCH, the reception-ON period is extended and the data reception of the downlink control channel PDCCH and the downlink shared channel PDSCH is prepared.
The intermittent reception mode includes short DRX and long DRX, and the long DRX is a DRX having a longer DRX interval than the short DRX. First, the intermittent reception mode is started with the short DRX. If the downlink shared channel PDSCH is not assigned through the downlink control channel PDCCH for a certain period, a shift is made from the short DRX to the long DRX. FIG. 16 depicts a relationship among the continuous reception, the short DRX, and the long DRX. A short DRX interval is an interval of 2 ms to 640 ms; a long DRX interval is an interval of 10 ms to 2560 ms; and each of the intervals is specified by the base station apparatus.
The parameters related to the intermittent reception include a DRX interval, a reception-ON period of the downlink control channel PDCCH, a reception-ON extension period when the reception-ON period is extended if the downlink control channel PDCCH is received during the reception-ON period of the downlink control channel PDCCH, a DRX start position, and a reception-ON period at the time of retransmission, and are sent to a mobile station apparatus through a message of an RRC layer (Radio Resource Control Layer) (Non-Patent Literatures 3, 4, and 5).
3GPP has also started discussing Advanced-EUTRA, which is a further evolution from EUTRA. Advanced-EUTRA is assumed to use a band of up to 100-MHz bandwidth for each of uplink and downlink to perform communications with transmission rates of up to 1 Gbps or more for downlink and 500 Mbps or more for uplink.
As depicted in FIG. 17, it is also conceived for Advanced-EUTRA to bundle a plurality of 20-MHz bands of EUTRA to realize a 100-MHz band such that a 100-MHz band can be supported by a mobile station apparatus of EUTRA. One 20-MHz band of EUTRA is referred to as a component carrier (CC) in Advanced-EUTRA.